Dated URIs

Sometimes you need globally unique identifiers, such as for ISRCs. One way to approach this is by using URIs – the uniqueness of the domain part of URIs is administered by ICANN, the uniqueness of the rest of the URI is administered by the owner of the domain. There’s a good balance between centralization and decentralization.

But ownership of domains changes, and when it does the identifiers associated with one ownership become invalid. Many types of identifiers, including ISRCs, need to be persistent. So you couldn’t use URLs for these.

This could be corrected by adding a date to the identifier. The new identifier would be a URL/date pair, like

[“January 1, 2000”,””]

The date specifies a point in time when the identifier was valid. So if there is a valid identifier on January 1, 2000, and then comes under new management which doesn’t support this identifier, the dated URL continues to be valid.

This only works for URIs used as identifiers and not for URIs used as locators. Adding the date would not restore an old URI that was out of service.

4 thoughts on “Dated URIs

  1. That’s an incredibly interesting document. Really fun thinking.

    This document defines two URI schemes. The first, ‘duri’ (standing
    for “dated URI”), identifies a resource as of a particular time.
    This allows explicit reference to the “time of retrieval”, similar to
    the way in which bibliographic references containing URIs are often

    The second scheme, ‘tdb’ ( standing for “Thing Described By”),
    provides a way of minting URIs for anything that can be described, by
    the means of identifying a description as of a particular time.
    These schemes were posited as “thought experiments”, and therefore
    this document is designated as Experimental.

  2. Kick it up a notch:
    – Use URIs as identifiers
    – Retrieving that URI gives you a graph of facts
    – Some of those facts are about other “external” identifiers.
    – It’s all distributed and people can’t agree on everything.

    IE: states that the organisation identified by is a criminal organisation.

    … and you get into a whole lot of interesting Trust issues. is an attempt at attributing statements to agents/authors and tackles concepts like
    – X stating a fact
    – X stating on behalf of Y
    – X calculating a fact from A + B + C
    – X stated a fact at revision 1, X stated a contradiction of that fact at revision 2.

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